Solutions To Water Insecurity - Large scale water managment And CS - WATER CYCLE Flashcards
1
Q
Hard engineering approaches
A
- Mega dams
- Desalination plants
- Water transfer schemes
- intergrated managed scheme
2
Q
- Mega dams overview
A
Large structures over 15m in height with stores masses amounts of water
3
Q
4 Pros of Mega dams
A
- Provides large volume of water
- Irrigation
- Can generate hydroelectric power
- Reduces demand for groundwater
4
Q
7 cons of Mega dams
A
- Still floods land
- Expensive
- Landlsides ( Himalayas)
- CO2 intensive during construction phase
- 80 million people displaced
- Countries/ areas downstream and suffer from lack of water
- water stored on surface evaporates quickly
- concrete - production, for construction of dam releases CO2.
5
Q
Mega dam CASE STUDY - The three gorges dam Pros (3)
A
- Improve water supply by regulating river flow
- Genrate HEP and make river navigable
- Electricity generated vital for Chinas growth
6
Q
Mega dam CASE STUDY - The three gorges dam Cons (4)
A
- Controversial and expensive
- 632 km^2 of land has been flooded - to form the reservoir
- 1.3 million people relocated from 1500 villages and towns
- reservoirs water quality is low due to waste from industry, sewage and farms enter from upstream
- Decomposing vegetation in reservoir produces methane, which is released when water passes through HEP turbines
7
Q
- Desalination plants ( removes salt)
A
Uses reverse osmosis technology to separate water molecules from seawater
8
Q
2 Pros of Desalination plants
A
- Can provide a large volume of clean water
- Reduces demand for groundwater
- 1.4 million cubic metres of water daily ( Al- Jubail - largest facility)
- Benefits 7 million
9
Q
5 Cons of Desalination plants
A
- Energy intensive
- Releases lots of CO2
- Produces salt water
- Expensive to build/ maintain
- Brine is put back into water leading higher density and impacts ecosystem
10
Q
Desalination plants CASE STUDY - Israel Pros (3)
(and potentially Saudi)
A
- Five plants opened by 2013, taking water directly from Mediterranean Sea
- Aims to provide 70% of Israels domestic water supply
- Produces up to 600 tonnes of potable water per hr
11
Q
Desalination plants CASE STUDY - Israel Cons (2)
A
- Requires its own power station and adds to CO2 emissions, but much of is used for solar
- Produces vast amounts of salt/ brine containing anti scaling agents that harms ecosystems
12
Q
- Water transfer schemes Overview
A
When a country has a surplus income area and a water shortage in another area, supplies can be transferred
13
Q
2 Pros of Water transfers
A
- Can provide water for area that lack water and arid areas
- Water can become a valuable resource for countires otherwise poor and undeveloped
14
Q
4 Cons of Water transfers
A
- Can dry up source areas
- Expensive
- Lots of water evaporates
- People relocated so construction can occur
15
Q
Water transfer CASE STUDY - The south- North transfer project in China PROS (6)
A
- The Beijing region has 35% of chinas population and 40% or arable land, but 7% gets water access
- reduce risk of water shortages in Beijing and boost economic development
- Reduce abstraction of groundwater
- Improve irrigation, pollution treatment and environmental protection
- Transfer 44.8 billion cubic metres of water per yr
